REUTERS/Gary Cameron
Harry Reid.
Adam Jentleson, the Senate minority leader's deputy chief of staff, highlighted the Republican-controlled Senate's inaction on Supreme Court nominee Merrick Garland, among other issues.
"The Republican Senate refuses to hold hearings on Judge Garland, refuses to fund the President's request for Zika aid and takes the most days off of any Senate since 1956, but thinks Facebook hearings are a matter of urgent national interest," Jentleson wrote in an email.
"The taxpayers who pay Republican senators' salaries probably want their money back," he continued.
Jentleson's remarks came in response to a Tuesday letter from John Thune, a South Dakota senator, who announced the Senate Commerce Committee's launch of an inquiry into how Facebook curates its "trending" section.
The inquiry followed a Gizmodo story published Monday that featured claims from a former Facebook news curator, who said he is politically conservative, that the site allegedly suppressed conservative news from appearing on the trending module.
In Thune's letter, the senator asked Facebook CEO Mark Zuckerberg if curators "manipulated the content" of the trending section.
"Facebook must answer these serious allegations and hold those responsible to account if there has been political bias in the dissemination of trending news," Thune said in a statement. "Any attempt by a neutral and inclusive social media platform to censor or manipulate political discussion is an abuse of trust and inconsistent with the values of an open Internet."